/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "jit/IonAnalysis.h"
#include "jit/MIRGenerator.h"
#include "jit/MIRGraph.h"
#include "jit/RangeAnalysis.h"
#include "jit/ValueNumbering.h"

#include "jsapi-tests/testJitMinimalFunc.h"
#include "jsapi-tests/tests.h"

using namespace js;
using namespace js::jit;

static MBasicBlock*
FollowTrivialGotos(MBasicBlock* block)
{
    while (block->phisEmpty() && *block->begin() == block->lastIns() && block->lastIns()->isGoto())
        block = block->lastIns()->toGoto()->getSuccessor(0);
    return block;
}

BEGIN_TEST(testJitGVN_FixupOSROnlyLoop)
{
    // This is a testcase which constructs the very rare circumstances that
    // require the FixupOSROnlyLoop logic.

    MinimalFunc func;

    MBasicBlock* entry = func.createEntryBlock();
    MBasicBlock* osrEntry = func.createOsrEntryBlock();
    MBasicBlock* outerHeader = func.createBlock(entry);
    MBasicBlock* merge = func.createBlock(outerHeader);
    MBasicBlock* innerHeader = func.createBlock(merge);
    MBasicBlock* innerBackedge = func.createBlock(innerHeader);
    MBasicBlock* outerBackedge = func.createBlock(innerHeader);
    MBasicBlock* exit = func.createBlock(outerHeader);

    MConstant* c = MConstant::New(func.alloc, BooleanValue(false));
    entry->add(c);
    entry->end(MTest::New(func.alloc, c, outerHeader, exit));
    osrEntry->end(MGoto::New(func.alloc, merge));

    merge->end(MGoto::New(func.alloc, innerHeader));

    // Use Beta nodes to hide the constants and suppress folding.
    MConstant* x = MConstant::New(func.alloc, BooleanValue(false));
    outerHeader->add(x);
    MBeta* xBeta = MBeta::New(func.alloc, x, Range::NewInt32Range(func.alloc, 0, 1));
    outerHeader->add(xBeta);
    outerHeader->end(MTest::New(func.alloc, xBeta, merge, exit));

    MConstant* y = MConstant::New(func.alloc, BooleanValue(false));
    innerHeader->add(y);
    MBeta* yBeta = MBeta::New(func.alloc, y, Range::NewInt32Range(func.alloc, 0, 1));
    innerHeader->add(yBeta);
    innerHeader->end(MTest::New(func.alloc, yBeta, innerBackedge, outerBackedge));

    innerBackedge->end(MGoto::New(func.alloc, innerHeader));
    outerBackedge->end(MGoto::New(func.alloc, outerHeader));

    MConstant* u = MConstant::New(func.alloc, UndefinedValue());
    exit->add(u);
    exit->end(MReturn::New(func.alloc, u));

    MOZ_ALWAYS_TRUE(innerHeader->addPredecessorWithoutPhis(innerBackedge));
    MOZ_ALWAYS_TRUE(outerHeader->addPredecessorWithoutPhis(outerBackedge));
    MOZ_ALWAYS_TRUE(exit->addPredecessorWithoutPhis(entry));
    MOZ_ALWAYS_TRUE(merge->addPredecessorWithoutPhis(osrEntry));

    outerHeader->setLoopHeader(outerBackedge);
    innerHeader->setLoopHeader(innerBackedge);

    if (!func.runGVN())
        return false;

    // The loops are no longer reachable from the normal entry. They are
    // doinated by the osrEntry.
    MOZ_RELEASE_ASSERT(func.graph.osrBlock() == osrEntry);
    MBasicBlock* newInner = FollowTrivialGotos(osrEntry->lastIns()->toGoto()->target());
    MBasicBlock* newOuter = FollowTrivialGotos(newInner->lastIns()->toTest()->ifFalse());
    MBasicBlock* newExit = FollowTrivialGotos(entry);
    MOZ_RELEASE_ASSERT(newInner->isLoopHeader());
    MOZ_RELEASE_ASSERT(newOuter->isLoopHeader());
    MOZ_RELEASE_ASSERT(newExit->lastIns()->isReturn());

    // One more time.
    ClearDominatorTree(func.graph);
    if (!func.runGVN())
        return false;

    // The loops are no longer reachable from the normal entry. They are
    // doinated by the osrEntry.
    MOZ_RELEASE_ASSERT(func.graph.osrBlock() == osrEntry);
    newInner = FollowTrivialGotos(osrEntry->lastIns()->toGoto()->target());
    newOuter = FollowTrivialGotos(newInner->lastIns()->toTest()->ifFalse());
    newExit = FollowTrivialGotos(entry);
    MOZ_RELEASE_ASSERT(newInner->isLoopHeader());
    MOZ_RELEASE_ASSERT(newOuter->isLoopHeader());
    MOZ_RELEASE_ASSERT(newExit->lastIns()->isReturn());

    return true;
}
END_TEST(testJitGVN_FixupOSROnlyLoop)

BEGIN_TEST(testJitGVN_FixupOSROnlyLoopNested)
{
    // Same as testJitGVN_FixupOSROnlyLoop but adds another level of loop
    // nesting for added excitement.

    MinimalFunc func;

    MBasicBlock* entry = func.createEntryBlock();
    MBasicBlock* osrEntry = func.createOsrEntryBlock();
    MBasicBlock* outerHeader = func.createBlock(entry);
    MBasicBlock* middleHeader = func.createBlock(outerHeader);
    MBasicBlock* merge = func.createBlock(middleHeader);
    MBasicBlock* innerHeader = func.createBlock(merge);
    MBasicBlock* innerBackedge = func.createBlock(innerHeader);
    MBasicBlock* middleBackedge = func.createBlock(innerHeader);
    MBasicBlock* outerBackedge = func.createBlock(middleHeader);
    MBasicBlock* exit = func.createBlock(outerHeader);

    MConstant* c = MConstant::New(func.alloc, BooleanValue(false));
    entry->add(c);
    entry->end(MTest::New(func.alloc, c, outerHeader, exit));
    osrEntry->end(MGoto::New(func.alloc, merge));

    merge->end(MGoto::New(func.alloc, innerHeader));

    // Use Beta nodes to hide the constants and suppress folding.
    MConstant* x = MConstant::New(func.alloc, BooleanValue(false));
    outerHeader->add(x);
    MBeta* xBeta = MBeta::New(func.alloc, x, Range::NewInt32Range(func.alloc, 0, 1));
    outerHeader->add(xBeta);
    outerHeader->end(MTest::New(func.alloc, xBeta, middleHeader, exit));

    MConstant* y = MConstant::New(func.alloc, BooleanValue(false));
    middleHeader->add(y);
    MBeta* yBeta = MBeta::New(func.alloc, y, Range::NewInt32Range(func.alloc, 0, 1));
    middleHeader->add(yBeta);
    middleHeader->end(MTest::New(func.alloc, yBeta, merge, outerBackedge));

    MConstant* w = MConstant::New(func.alloc, BooleanValue(false));
    innerHeader->add(w);
    MBeta* wBeta = MBeta::New(func.alloc, w, Range::NewInt32Range(func.alloc, 0, 1));
    innerHeader->add(wBeta);
    innerHeader->end(MTest::New(func.alloc, wBeta, innerBackedge, middleBackedge));

    innerBackedge->end(MGoto::New(func.alloc, innerHeader));
    middleBackedge->end(MGoto::New(func.alloc, middleHeader));
    outerBackedge->end(MGoto::New(func.alloc, outerHeader));

    MConstant* u = MConstant::New(func.alloc, UndefinedValue());
    exit->add(u);
    exit->end(MReturn::New(func.alloc, u));

    MOZ_ALWAYS_TRUE(innerHeader->addPredecessorWithoutPhis(innerBackedge));
    MOZ_ALWAYS_TRUE(middleHeader->addPredecessorWithoutPhis(middleBackedge));
    MOZ_ALWAYS_TRUE(outerHeader->addPredecessorWithoutPhis(outerBackedge));
    MOZ_ALWAYS_TRUE(exit->addPredecessorWithoutPhis(entry));
    MOZ_ALWAYS_TRUE(merge->addPredecessorWithoutPhis(osrEntry));

    outerHeader->setLoopHeader(outerBackedge);
    middleHeader->setLoopHeader(middleBackedge);
    innerHeader->setLoopHeader(innerBackedge);

    if (!func.runGVN())
        return false;

    // The loops are no longer reachable from the normal entry. They are
    // doinated by the osrEntry.
    MOZ_RELEASE_ASSERT(func.graph.osrBlock() == osrEntry);
    MBasicBlock* newInner = FollowTrivialGotos(osrEntry->lastIns()->toGoto()->target());
    MBasicBlock* newMiddle = FollowTrivialGotos(newInner->lastIns()->toTest()->ifFalse());
    MBasicBlock* newOuter = FollowTrivialGotos(newMiddle->lastIns()->toTest()->ifFalse());
    MBasicBlock* newExit = FollowTrivialGotos(entry);
    MOZ_RELEASE_ASSERT(newInner->isLoopHeader());
    MOZ_RELEASE_ASSERT(newMiddle->isLoopHeader());
    MOZ_RELEASE_ASSERT(newOuter->isLoopHeader());
    MOZ_RELEASE_ASSERT(newExit->lastIns()->isReturn());

    // One more time.
    ClearDominatorTree(func.graph);
    if (!func.runGVN())
        return false;

    // The loops are no longer reachable from the normal entry. They are
    // doinated by the osrEntry.
    MOZ_RELEASE_ASSERT(func.graph.osrBlock() == osrEntry);
    newInner = FollowTrivialGotos(osrEntry->lastIns()->toGoto()->target());
    newMiddle = FollowTrivialGotos(newInner->lastIns()->toTest()->ifFalse());
    newOuter = FollowTrivialGotos(newMiddle->lastIns()->toTest()->ifFalse());
    newExit = FollowTrivialGotos(entry);
    MOZ_RELEASE_ASSERT(newInner->isLoopHeader());
    MOZ_RELEASE_ASSERT(newMiddle->isLoopHeader());
    MOZ_RELEASE_ASSERT(newOuter->isLoopHeader());
    MOZ_RELEASE_ASSERT(newExit->lastIns()->isReturn());

    return true;
}
END_TEST(testJitGVN_FixupOSROnlyLoopNested)

BEGIN_TEST(testJitGVN_PinnedPhis)
{
    // Set up a loop which gets optimized away, with phis which must be
    // cleaned up, permitting more phis to be cleaned up.

    MinimalFunc func;

    MBasicBlock* entry = func.createEntryBlock();
    MBasicBlock* outerHeader = func.createBlock(entry);
    MBasicBlock* outerBlock = func.createBlock(outerHeader);
    MBasicBlock* innerHeader = func.createBlock(outerBlock);
    MBasicBlock* innerBackedge = func.createBlock(innerHeader);
    MBasicBlock* exit = func.createBlock(innerHeader);

    MPhi* phi0 = MPhi::New(func.alloc);
    MPhi* phi1 = MPhi::New(func.alloc);
    MPhi* phi2 = MPhi::New(func.alloc);
    MPhi* phi3 = MPhi::New(func.alloc);

    MParameter* p = func.createParameter();
    entry->add(p);
    MConstant* z0 = MConstant::New(func.alloc, Int32Value(0));
    MConstant* z1 = MConstant::New(func.alloc, Int32Value(1));
    MConstant* z2 = MConstant::New(func.alloc, Int32Value(2));
    MConstant* z3 = MConstant::New(func.alloc, Int32Value(2));
    MOZ_RELEASE_ASSERT(phi0->addInputSlow(z0));
    MOZ_RELEASE_ASSERT(phi1->addInputSlow(z1));
    MOZ_RELEASE_ASSERT(phi2->addInputSlow(z2));
    MOZ_RELEASE_ASSERT(phi3->addInputSlow(z3));
    entry->add(z0);
    entry->add(z1);
    entry->add(z2);
    entry->add(z3);
    entry->end(MGoto::New(func.alloc, outerHeader));

    outerHeader->addPhi(phi0);
    outerHeader->addPhi(phi1);
    outerHeader->addPhi(phi2);
    outerHeader->addPhi(phi3);
    outerHeader->end(MGoto::New(func.alloc, outerBlock));

    outerBlock->end(MGoto::New(func.alloc, innerHeader));

    MConstant* true_ = MConstant::New(func.alloc, BooleanValue(true));
    innerHeader->add(true_);
    innerHeader->end(MTest::New(func.alloc, true_, innerBackedge, exit));

    innerBackedge->end(MGoto::New(func.alloc, innerHeader));

    MInstruction* z4 = MAdd::New(func.alloc, phi0, phi1);
    MConstant* z5 = MConstant::New(func.alloc, Int32Value(4));
    MInstruction* z6 = MAdd::New(func.alloc, phi2, phi3);
    MConstant* z7 = MConstant::New(func.alloc, Int32Value(6));
    MOZ_RELEASE_ASSERT(phi0->addInputSlow(z4));
    MOZ_RELEASE_ASSERT(phi1->addInputSlow(z5));
    MOZ_RELEASE_ASSERT(phi2->addInputSlow(z6));
    MOZ_RELEASE_ASSERT(phi3->addInputSlow(z7));
    exit->add(z4);
    exit->add(z5);
    exit->add(z6);
    exit->add(z7);
    exit->end(MGoto::New(func.alloc, outerHeader));

    MOZ_ALWAYS_TRUE(innerHeader->addPredecessorWithoutPhis(innerBackedge));
    MOZ_ALWAYS_TRUE(outerHeader->addPredecessorWithoutPhis(exit));

    outerHeader->setLoopHeader(exit);
    innerHeader->setLoopHeader(innerBackedge);

    if (!func.runGVN())
        return false;

    MOZ_RELEASE_ASSERT(innerHeader->phisEmpty());
    MOZ_RELEASE_ASSERT(exit->isDead());

    return true;
}
END_TEST(testJitGVN_PinnedPhis)
